Glaucoma is the second leading cause of blindness worldwide, and is especially prevalent among African Americans. There are many different types of glaucoma, but all share the common defining feature of retinal ganglion cell death. The overall goal of this proposal is to use recently developed techniques to understand better the molecular events underlying the death of retinal ganglion cells in glaucoma. This will likely lead to new treatments for glaucoma and other diseases of the optic nerve. My working hypothesis is that intraocular pressure, as well as other as yet unknown insults, leads to changes in gene expression that characterize the ganglion cell response to injury, from initial insult to induction of cell death mechanisms. The long- term goal is to understand the function of these genes so that they can be therapeutically modulated in glaucoma to prevent or delay retinal ganglion cell death. The murine glaucoma model is proposed as a system for analysis, for reasons that are described in the application. The first specific aim is to identify genes that are differentially expressed in the retina of mice with "glaucoma." To accomplish this, the technique of 'serial analysis of gene expression' (SAGE) will be applied to whole retinal tissue. Genes that demonstrate significant differences in expression level will be selected for detailed study. A key advantage of this approach is that it can identify, free of preconceived bias, previously unsuspected genes that may be important in glaucoma, as opposed to a 'candidate gene' approach that might focus, for example, solely on genes related to apoptosis or growth factors. The second specific aim is to isolate pure retinal ganglion cells for use in similar gene expression studies. The use of purified ganglion cells will allow for high-resolution investigation of gene expression changes specific to ganglion cells. To accomplish these aims, technologies for gene expression analysis will be refined and developed. A combination of research and didactic activities will contribute to the training value of the proposal by focusing both on currently achievable scientific ends and on the skills needed by the primary investigator for a future independent research career. The Wilmer Ophthalmological Institute at Johns Hopkins University, and the sponsor's laboratory in particular, provide an ideal environment for the candidate to pursue these goals.